Primary skin fibroblasts obtained from individuals diagnosed with late-onset sporadic Parkinson's disease (PD), were compared to healthy age-matched controls. Fibroblasts from PD subjects had higher growth rates, and appeared distinctly different in terms of morphology and spatial organization in culture, compared to control cells. The PD fibroblasts also exhibited significantly compromised mitochondrial structure and function when assessed via morphological and oxidative phosphorylation assays. Additionally, an increase in baseline macroautophagy levels was seen in cells from PD subjects. Exposure of the skin fibroblasts to physiologically relevant stress, specifically ultraviolet irradiation (UVA), further exaggerated the autophagic dysfunction in the PD cells. Moreover, the PD fibroblasts accumulated higher levels of reactive oxygen species (ROS) coupled with lower cell viability upon UVA treatment. These results highlight primary skin fibroblasts as a patient-relevant model that captures fundamental PD molecular mechanisms, and enable their utility as diagnostic and prognostic biomarkers for PD.